/*
 * Copyright (C) 2007 The Guava Authors
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 * http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package bma.common.langutil.core;


/**
 * Determines an output value based on an input value.
 * 
 * @author Kevin Bourrillion
 * @since 2.0 (imported from Google Collections Library)
 */
public interface Function<F, T> {
	/**
	 * Returns the result of applying this function to {@code input}. This
	 * method is <i>generally expected</i>, but not absolutely required, to have
	 * the following properties:
	 * 
	 * <ul>
	 * <li>Its execution does not cause any observable side effects.
	 * <li>The computation is <i>consistent with equals</i>; that is,
	 * {@link Objects#equal Objects.equal}{@code (a, b)} implies that
	 * {@code Objects.equal(function.apply(a), function.apply(b))}.
	 * </ul>
	 * 
	 * @throws NullPointerException
	 *             if {@code input} is null and this function does not accept
	 *             null arguments
	 */
	T apply(F input);	
}
